Too many clinkers?

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mtnbiker727

Burning Hunk
Mar 11, 2019
220
PA
Yep. The combustion fan—the one behind the ash bucket—was running intermittently today in test mode while I was cleaning the stove. That's a problem, correct?
I haven't experienced it turning off on me like that. I would think it's probably not good? Maybe someone else will chime in with their thoughts.
 

Nitro-Fish

Burning Hunk
Feb 5, 2009
163
VA
Not overthinking! Ash line should move when stove set to max on manual, and it doesn't. Will discuss with Harman tech when they come next spring.
You are putting way too much worry in the ash line, the ESP will only let the stove burn so much at a given time; even when set to wide open, once a certain temp is reached at the probe, that's it no more, and the Harman's have no problem getting there fast. As far as rear covers, the stove doesn't care, it will run with or without them. You might want to read through the sticky about your Harman stove, what the manual doesn't tell you, at the beginning of this forum, it may help you understand the operation. I have several Harman stoves and the ash line is not even a thought for me, set it up right, burn it and be happy; between the room temp sensor and the ESP, the stove is smarter than you think. If you are not getting heat, you likely have exhaust vent issues, all they are is a big old air pump, cool or room temp air in depending on OAK or not (and I have both set-ups) and heated air out, if it's not passing air right, it will not be happy. As far as the oil filter wrench on the clean out, if you are worried about the cap not moving because of sealant, use two; one to hold the tee from moving the other on the clean-out cap, easy-peasy.
 
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anon_ymous

New Member
Nov 16, 2021
39
Chesley, Ont.
I haven't experienced it turning off on me like that. I would think it's probably not good? Maybe someone else will chime in with their thoughts.
Thanks, Mtnbiker! Fingers crossed!! If not, I'll reach out to the regional Harman tech tomorrow...
 

Washed-Up

Minister of Fire
Nov 5, 2011
884
Kananaskis,Alberta, Canada
That’s right, the combustion fan should stay on in test mode
 

Nitro-Fish

Burning Hunk
Feb 5, 2009
163
VA
Is the combustion fan supposed to be running continually in "test" mode? Mine seems to be cycling and / or intermittent.
After 1 minute in test mode the combustion blower will return to a low burn rate simulation, is yours going off completely or just ramping down? Also, the ash line is something that you compare after say an hours worth of use, it is controlled by the feed rate, which is typically found to be ideal between 3 and 4, I will set this at initial set up with a clean pot to begin with, not after the stove has been burning.
 
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Nitro-Fish

Burning Hunk
Feb 5, 2009
163
VA
I cleaned the [very dirty] ESP sensor and ran the test to determine the optimal feed limit. I followed the instructions in the manual, but the burn line seems unaffected when I increase it from 4 to 6,

"With the unit burning in “AUTO”, turn to “Constant Burn” and put the fan on “H”. Set the Temperature Dial to #7."
Taken from the rest of the paragraph you are referencing in the manual: "Allow the unit to burn for about 30
minutes and check ash on front of burn pot. Figure 4.7. If the
ash line is larger than 1", turn the feed limit from #4 to #5. Allow
another 30 minutes of burn time and check again. If, at #6 setting,
a 1" or less ash bed is not obtainable, it is not a problem......"
 

anon_ymous

New Member
Nov 16, 2021
39
Chesley, Ont.
After 1 minute in test mode the combustion blower will return to a low burn rate simulation, is yours going off completely or just ramping down? Also, the ash line is something that you compare after say an hours worth of use, it is controlled by the feed rate, which is typically found to be ideal between 3 and 4, I will set this at initial set up with a clean pot to begin with, not after the stove has been burning.
Thanks, Nitro! It was def running very slowly, and at one point it stopped; next time I clean out the stove, I'll pay closer attention.

Re: the ash line, I waited 30min before tuning up the feed rate at max temp on the stove, as per the instructions in the manual. Ran maybe 2h, but didn't see any change :/
 

anon_ymous

New Member
Nov 16, 2021
39
Chesley, Ont.
Taken from the rest of the paragraph you are referencing in the manual: "Allow the unit to burn for about 30
minutes and check ash on front of burn pot. Figure 4.7. If the
ash line is larger than 1", turn the feed limit from #4 to #5. Allow
another 30 minutes of burn time and check again. If, at #6 setting,
a 1" or less ash bed is not obtainable, it is not a problem......"
Yes, exactly; I followed these instructions. You'd think I'd have seen _some_ movement?
 

Ocelot

Burning Hunk
Dec 27, 2010
102
Hudson Valley, NY
At first I was confused about the ash line since the ESP controls the feed anyway, but the sticky thread got it to make sense to me. As I understand it now, the idea is that if the ESP for example is calling for as much heat as the stove can put out and the feed knob is too high, unburnt pellets might be dumping over the side wasting pellets. On the other hand, if the feed knob is too low and the ash line can't get to within one inch of the edge, then you won't get as much heat out of the stove as possible if the ESP is calling for max heat. So setting the feed knob so that at full bore the ash line is about 1 inch from the edge, you get the most possible heat when the ESP wants it without dumping not fully burnt pellets over the edge of the burn pot.

Does that sound correct, or am I still missing something?

Ray
 
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Washed-Up

Minister of Fire
Nov 5, 2011
884
Kananaskis,Alberta, Canada
The ESP will call for pellets until the temperature it is set for is reached. The one inch line is the “ideal” and ,depending on pellet quality, is not always met…I’ve run my stove full bore a few times and have never met the one inch ash mark…you do have a better understanding of it from the looks of it.
 

Mt Bob

Minister of Fire
Oct 31, 2013
3,660
park county montana
At first I was confused about the ash line since the ESP controls the feed anyway, but the sticky thread got it to make sense to me. As I understand it now, the idea is that if the ESP for example is calling for as much heat as the stove can put out and the feed knob is too high, unburnt pellets might be dumping over the side wasting pellets. On the other hand, if the feed knob is too low and the ash line can't get to within one inch of the edge, then you won't get as much heat out of the stove as possible if the ESP is calling for max heat. So setting the feed knob so that at full bore the ash line is about 1 inch from the edge, you get the most possible heat when the ESP wants it without dumping not fully burnt pellets over the edge of the burn pot.

Does that sound correct, or am I still missing something?

Ray
Yes,you got it.
 
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Mt Bob

Minister of Fire
Oct 31, 2013
3,660
park county montana
After 1 minute in test mode the combustion blower will return to a low burn rate simulation, is yours going off completely or just ramping down? Also, the ash line is something that you compare after say an hours worth of use, it is controlled by the feed rate, which is typically found to be ideal between 3 and 4, I will set this at initial set up with a clean pot to begin with, not after the stove has been burning.
Yes. Have seen on some older control boards it runs on hi always,newer boards it drops back,as you said. Which is annoying with the new boards,for running it when cleaning.Easier to just turn stove on, open door, fan will run forever until door is shut.
 

anon_ymous

New Member
Nov 16, 2021
39
Chesley, Ont.
Does the stove heat the space you're intending on heating?
I'd say yes, but we're burning through a lot of pellets. I'm a little concerned about trying to get the Tee cap off with an oil filter wrench to clean what I could of the vent pipe in the event that I damage it, as the tech isn't keen on coming out here until next Spring (at which point, they'll also clean the chimney)... I may call Duravent on Monday, to see what they suggest about whether it would be worth risking trying to get the Tee cap off.

Yes. Have seen on some older control boards it runs on hi always,newer boards it drops back,as you said. Which is annoying with the new boards,for running it when cleaning.Easier to just turn stove on, open door, fan will run forever until door is shut.
I'm pretty sure mine's the older board—it's a 2015. If you guys confirm this, would it be safe to say that the fan should have been running full speed continually?
 

Mt Bob

Minister of Fire
Oct 31, 2013
3,660
park county montana
I'd say yes, but we're burning through a lot of pellets. I'm a little concerned about trying to get the Tee cap off with an oil filter wrench to clean what I could of the vent pipe in the event that I damage it, as the tech isn't keen on coming out here until next Spring (at which point, they'll also clean the chimney)... I may call Duravent on Monday, to see what they suggest about whether it would be worth risking trying to get the Tee cap off.


I'm pretty sure mine's the older board—it's a 2015. If you guys confirm this, would it be safe to say that the fan should have been running full speed continually?
Don't have my chart in front of me, but "older" would be 2010 and back. But,as you are not sure about the way your unit is functioning, a replacement board is pretty cheap to buy and try. Have seen them less than 200 bucks.
 

anon_ymous

New Member
Nov 16, 2021
39
Chesley, Ont.
Don't have my chart in front of me, but "older" would be 2010 and back. But,as you are not sure about the way your unit is functioning, a replacement board is pretty cheap to buy and try. Have seen them less than 200 bucks.
Thanks! I'll do a little research...
 
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anon_ymous

New Member
Nov 16, 2021
39
Chesley, Ont.
OK! I managed to remove the Duravent Tee cap and clean out the first 3 ft of stovepipe + behind the cover for the combustion blower (I removed the ESP sensor first and cleaned it as well).

BUT then, these three pieces came out... they seem like rusty gasket? Anyone know what they are? Or whether I can run the stove?

Also, I noticed that once I seated and screwed back in the 1/4" bolt that attaches the ESP sensor, that the ESP sensor is a little loose/I can pull the wire leading to the sensor in and out a little bit—is that normal?

Rusty bits.jpeg
 
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Washed-Up

Minister of Fire
Nov 5, 2011
884
Kananaskis,Alberta, Canada
Just put a dab of RTV on the seat of the ESP to seal it….If those pieces came out of the exhaust vent, they’re the crappy gasket material they come with, just make sure to use a good seal with metal foil tape when reconnecting
 

anon_ymous

New Member
Nov 16, 2021
39
Chesley, Ont.
Just put a dab of RTV on the seat of the ESP to seal it….If those pieces came out of the exhaust vent, they’re the crappy gasket material they come with, just make sure to use a good seal with metal foil tape when reconnecting
Thanks, Washed-Up! Fingers crossed, the stove will soon be running more efficiently :)

Is this flange where the gasket on the interior was? Shouldn't I be putting RTV on it (outside), rather than foil tape? Given that a piece of gasket literally fell out of the Tee when I opened it, at least part of the gasket hadn't been attached for a while, any reason I couldn't run the stove without, until I could get some RTV? (someone in the house didn't close the cap, so the RTV we have here dried out!)

The local Harman repair (who are closed for the holidays) mentioned to me a while ago that if there's anything wrong with the stove, it will shut down/not run—I'm assuming that would be the case for seals as well?

flange.JPG
 
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Ocelot

Burning Hunk
Dec 27, 2010
102
Hudson Valley, NY
Thanks, Washed-Up! Fingers crossed, the stove will soon be running more efficiently :)

Is this flange where the gasket on the interior was? Shouldn't I be putting RTV on it (outside), rather than foil tape? Given that a piece of gasket literally fell out of the Tee when I opened it, at least part of the gasket hadn't been attached for a while, any reason I couldn't run the stove without, until I could get some RTV? (someone in the house didn't close the cap, so the RTV we have here dried out!)

The local Harman repair (who are closed for the holidays) mentioned to me a while ago that if there's anything wrong with the stove, it will shut down/not run—I'm assuming that would be the case for seals as well?

View attachment 288835
If that's the exhaust port and it leaks, it won't cause the stove to shut down, but it could leak smoke into the house. I would check it with a flashlight when the stove is starting up to see if you see any smoke leaking. If so, silicone where it leaks, at least until you can get the proper gasket. I believe this would be the one, but doublecheck:
https://pellet-stove-parts-4less.co...68/products/harman-tailpipe-gasket-1-00-07381

On my P43 which is similar, I had a small smoke leak where the vent pipe connects to that tailpiece like shown in your picture and I siliconed the outside where the two pieces connect and that took care of it.
 

anon_ymous

New Member
Nov 16, 2021
39
Chesley, Ont.
If that's the exhaust port and it leaks, it won't cause the stove to shut down, but it could leak smoke into the house. I would check it with a flashlight when the stove is starting up to see if you see any smoke leaking. If so, silicone where it leaks, at least until you can get the proper gasket. I believe this would be the one, but doublecheck:
https://pellet-stove-parts-4less.co...68/products/harman-tailpipe-gasket-1-00-07381

On my P43 which is similar, I had a small smoke leak where the vent pipe connects to that tailpiece like shown in your picture and I siliconed the outside where the two pieces connect and that took care of it.
Well, I've gotta say, the timing of your reply was impeccable. As luck would have it, the pump on our oil furnace died this AM, and given the holiday, we're not going to be able to get a new pump until at least Monday.

I've fired up the Harman, and not a lick of smoke—that I can detect. I'll keep monitoring, but it seems to me that the gasket was in such rough shape that it hadn't been doing any good anyway. Our local(ish) Harman repair re-opens next week, so I'll confirm with them, then order the part.

Thank you so much! :)
 

Washed-Up

Minister of Fire
Nov 5, 2011
884
Kananaskis,Alberta, Canada
Definitely keep an eye on that coupling, and if you’re having difficulty finding a “Harman” gasket, I’ve ordered sheets of 1/8” silicone and cut them to fit on a few tailpipes with success
 

anon_ymous

New Member
Nov 16, 2021
39
Chesley, Ont.
Definitely keep an eye on that coupling, and if you’re having difficulty finding a “Harman” gasket, I’ve ordered sheets of 1/8” silicone and cut them to fit on a few tailpipes with success
If that's the exhaust port and it leaks, it won't cause the stove to shut down, but it could leak smoke into the house. I would check it with a flashlight when the stove is starting up to see if you see any smoke leaking. If so, silicone where it leaks, at least until you can get the proper gasket. I believe this would be the one, but doublecheck:
https://pellet-stove-parts-4less.co...68/products/harman-tailpipe-gasket-1-00-07381

On my P43 which is similar, I had a small smoke leak where the vent pipe connects to that tailpiece like shown in your picture and I siliconed the outside where the two pieces connect and that took care of it.
Thanks, both!

Could those pieces be anything other than this gasket? They seem like rusted metal, rather than silicone—but maybe that's what extreme heat does to silicone over the course of years!?

Assuming it's the gasket, is replacing it just as simple as unbolting the flange from the outside, sliding in the gasket, and replacing the bolts? Any reason I'd even have to disconnect the stovepipe?

BTW, stove is running hotter/better flame/(I think?) more efficiently since I removed the offending parts. This is a great group! Thanks!!
 

Washed-Up

Minister of Fire
Nov 5, 2011
884
Kananaskis,Alberta, Canada
Most likely….LIOTHERM 'PAPER' STYLE GASKET MATERIAL
And that’s are the sheets I’ve ordered in the past, super handy
Silicone Sheet Gasket, Red, 1/8"... Amazon product